Question

If prices increase at a monthly rate of 3.5%, by what percentage do they increase in a year ?

Answer 1

`51.1%`

Explanation:

The growth factor for one month is `g_"month"=1.035`.

There are `12` months in a year, and every month the price increases with factor `g_"month"`. So after a year the price will have increased with factor `g_"month"^12=1.035^12~~1.511`.
The price therefore increases with `51.1%`.